code: def get_pp_first() -> Callable[[tf.Tensor], tf.Tensor]:
      """PP op to select the first text out of many."""
  
      def _first(
          sequence: tf.Tensor,  # Any shape
      ) -> tf.Tensor:  # Shape: ()
          return tf.reshape(sequence, (-1,))[0]
  
      return _first
  
file_path: scenic/scenic/projects/lang4video/pp_ops.py
imports: from collections.abc import Callable
  import functools
  from typing import Optional
  from dmvr import processors
  from dmvr import tokenizers
  import ml_collections
  from scenic.dataset_lib.big_transfer.preprocessing import utils
  from scenic.dataset_lib.big_transfer.registry import Registry
  from scenic.projects.lang4video import util
  import tensorflow
label_desc: Use image node_id 3 for calling a global function with example usage: get_pp_first() and returns: _first, tf